There has been a 10 percent increase in the number of years that New Zealanders are staying in paid work since a mandatory retirement age was eliminated in 2000.
A paper by the Retirement Commission suggested income testing would be a fair way to reduce the cost of the system.
It comes as National and Labour are debating about whether to raise New Zealand's super age.
The new results show what's changed to a similar report in 2014.
Brad Olsen warns a "really big cost pressure" is going to hit New Zealand in the years to come.
"So single living with someone you're not married to or you're not in partnership with is more advantageous, which seems a little ridiculous."
The gender pay gap has also played a part, with men having 20 percent more retirement savings than women.
It comes after a warning from the OECD.
